About 3 weeks ago, I got CEL (check engine light) (2 codes 0440, and code 0441 and 0446), about 3 days after gasoline fill-up. I reset the CEL and retightened gas cap. I drove over 1,000 miles, from Maryland to Florida, with no problems.

I got CEL again today (codes 0440, 0441, 0446, 0440 pending, 0441 pending, and 0446 pending). Also 3 days after gasoline refill. I reset CEL, and tightened gas cap again.

No loose hoses that I can see. Any suggestions what to try?

 

Did you check the hose behind the air filter box? That seems to be the cause of this particular code most often.

This thread has a bunch of possible solutions: https://www.clublexus.com/forums/rx-...-po-446-a.html

 

I can confirm that those codes are a loose or broken vacuum return hose. I just had those codes recently. Its under the the intake hose, at least thats where it was on my car

 

You guys are the greatest!

I looked again under optimal lighting conditions. There was a detached hose. It was behind and below the air cleaner. It was at the point of attachment to the metal tube going presumably to the charcoal canister, and the rubber hose was going to what I think might be a solenoid attached to the air cleaner housing.

It's amazing that it only triggered the CEL twice in over 1,000 miles. I presume that was the cause of the CEL.